N-isopropyl-phosphoro-amido-thioates

ABSTRACT

N-isopropyl-phosphoro-amido-thioates, i.e., 0-(2-nitro-4-alkoxyphenyl)-0-alkyl-N-isopropyl-phosphoro-amido-thioates or 0-(2nitro-4-alkoxy-phenyl)-0-alkyl-N-isopropyl-amidothionophosphates, which possess herbicidal properties and which may be produced by conventional methods.

United States Patent Schrader et al.

[ Mar. 12, 1974 N-ISOPROPYL-PHOSPHORO-AMIDO- THIOATES [75] Inventors: Gerhard Schrader,

Wuppertal-Cronenberg; Ludwig Eue, Cologne-Stammheim; Helmuth Hack, Cologne-Buchheim, all of Germany; Seiiehi Hirane; Masahiro Aya; Shigeo Kishino; Nobuo Fukazawa, all of Tokyo, Japan [73] Assignee: Bayer Aktiengesellsehaft, V

Leverkusen, Germany [22] Filed: May 17, 1972 [2]] Appl. No.: 254,144

Related US. Application Data [62] Division of Ser. No. 867,875, Oct. 20, I969, Pat. No.

[30] Foreign Application Priority Data Oct. 28, I968 Japan 43/78424 [52] US. Cl. 71/87 [51] Int. Cl A0ln 9/36 [58] Field of Search 71/87 56] References Cited UNITED STATES PATENTS 3,472,920 10/1969 Schrader et al 71/87 Primary ExaminerLewis Gotts Assistant Examiner-Catherine L. Mills Attorney, Agent, or FirmBurgess, Dinklage & Sprung [57] ABSTRACT N-isopropyl-phosphoro-amido-thioates, .i.e.. 0-(2- nitro-4-alkoxy-phenyl)-O-alkyl-N-isopropylphosphoro-amido-thioates or O-(2-nitro-4-alkoxyphenyl)-O-alkyl-N-isopropyl-amido-thionophosphates, which possess herbicidal properties and which may be produced by conventional methods.

14 Claims, N0 Drawings This is a division of application Ser. No. 867,875 filed Oct. 20, 1969, now US. Pat. No. 3,705,929.

The present invention relates to and has for its objects the provision for particular new N-isopropyl-phosphoroamido-thioates, i.e., 2-nitro-4-alkoxy-phenyl)- O-alkyl-N-isopropyl-phosphoro-amido thioates or 0-( 2- nitro-4-alkoxyphenyl)-0-alkyl-N-isopropyl-amidothionophosphates, which possess herbicidal properties, active compositions in the form of mixtures of such compounds with solid and liquid dispersible carrier vehicles, and methods for producing such compounds and for using such compounds in a new way, especially for combating weeds, undesired plants, and the like, with other and further objects becoming apparent from a study of the within specification and accompanying examples.

It is already known that pentachloro-phenol (A), commonly known as PCP, and 2,4-dichloro-phenyl-4'- nitrophenyl-ether (B), commonly known as NIP, as well as 2-chloro-4,6-bis(ethylamino)-1,3,5-triazine (C), commonly known as CAT or Simazin, possess herbicidal properties.

It is furthennore known from British Pat. No. 659,6- 82 that amide-thionophosphoric acid esters of the formula in which R is an alkyi a ltnyi radical, 12, an alkyl radical, R is an alkyl radical or a hydrogen atom, and one X is a nitro radical and the other X is a hydrogen atom or a nitro radical, possess insecticidal and fungicidal properties. In said British Patent, itis indicated only that such compounds have insecticidal and acaricidal activity as well as activity for the control of harmful fungi on plants, and that they can be used in the form of spray preparations. However, there is no actual test data showing their efficacy, and no indication that such compoundsmight have herbicidal activity. Furthermore, no mention is made of the applicability of such compounds to soil or of any reason to expect them to have herbicidal activity. On the other hand, US. Pat. No. 3,074,790 describes compounds, for example 0- (2,4-dichloro-phenyl )-0-m ethyl-N-isopropylphosphoro-amido-thioate (D), which have herbicidal properties.

In accordance with applicants Japanese Pat. Appl. No. 78104/66 (filed on Nov. 30, 1966), it has been found that a certain derivative of this last-mentioned type of amido-thiono-phosphoric acid ester (which may be prepared in the same manner as the compounds of the present invention) has especially excellent herbicidal activity, to wit, O-( 2-nitro-phenyl)-O-methyl-N- isopropyl-phosphoro-amidothioate of the formula:

in which 2 It has now been found, in accordance with the present invention, that the particular new N-isopropylphosphoro-amido-thioates, i.e. 0-(2-nitro-4-alkoxyphenyl)-0-alkyl-N-isopropyl-phosphoro-amidothioates, of the formula LOQW prises (a) reacting an O-alkyl-N-isopropyl-amidothionophosphoric acid ester halide of the formula R0 5 l aal i-C3H7NH (II) in which R is the same as defined above, and Hal is a halogen atom such as chloro, bromo, iodo or fluoro, especially chloro, with a 2-nitro-4-alkoxy-phenol of the formula (III) in which R is the same as defined above, and M is hydrogen, or a cation such as an ammonium or alkali metal cation, for example potassium, sodium, and the like; or (b) reacting an N-isopropyl-amidothionophosphoric acid dihalide of the formula 8 Hal l-CaH7NH Hal (IV) Hal is the same as defined above, either with a 2-nitro-4-alkoxy-phenol of formula (III) and then with an alcoholate of the formula:

M O-R in which R is the same as defined above, and

M is a cation such as an alkali metal cation, for example potassium, sodium, and the like.

or with the alcoholate of formula (V), and then with the 2-nitro-4-alkoxy-phenol of formula (Ill).

Surprisingly, the particular new compounds according tothe present invention show both a higher and more specific herbicidal effectiveness than the previously known compounds which are known to be usable for such purposes, e.g., compounds (A), (B) and (C) above. The instant compounds are especially effective as pre-emergence herbicides, and exhibit a remarkable effect in killing weeds, with only slight, if any, phytotoxic effect toward cultivated plants such as rice. The instant compounds therefore represent a valuable contribution to the art.

Advantageously, in accordance with the present invention, in the various formulae herein:

R represents straight and branched chain lower alkyl hydrocarbon of one-four carbon atoms such as methyl, ethyl, nand iso-propyl, n-, iso-, sec.- and tert.-butyl, and the like, especially C or C alkyl; and R represents straight and branched chain lower alkyl hydrocarbon of one-four carbon atoms such as methyl to tertbutyl inclusive as defined above, and the like, especially C or methyl; R and R being the same or different. The reaction course according to process variant (a) is illustrated by the following formula scheme:

The starting materials which may be used for reaction variant (a) are clearly characterized by formulae (ll) and (III) above, and are well known.

The reaction course according to process variant (b) is illustrated by the following formula scheme:

The reaction course of the alternative of variant (b) is illustrated by the following formula scheme:

The starting materials which may be used for reaction variant (b) and the alternative of reaction variant (b) are clearly characterized by formulae (III), (IV) and (V) above, and are well known.

As examples of O-alkyl-N-isopropyl-amidothionophosphoric acid ester halides of formula (II) above which may be used as starting materials, there are mentioned: O-(methyl, ethyl, nand iso-propyl, n-, iso-, sec.- and tert.-butyl)-N-isopropyl-amido thionophosphoric acid ester chlorides, bromides, iodides and fluorides.

As examples of N-isopropyl-amido-thionophosphoric acid dihalides of formula (IV) above which may be used as starting materials, there are mentioned:

the corresponding di-chlorides, bromides, iodides and fluorides.

As examples of 2-nitro-4-alkoxy-phenols of formula (III) above which may be used as starting materials, there are mentioned:

2-nitro-4-(methoxy, ethoxy, nand iso-propoxy, n-,

iso-, sec.- and tert.-butoxy )-phenols, and the corresponding ammonium, potassium and sodium salts thereof.

As examples of alcoholates of formula (V) above which may be used as starting materials, there are mentioned:

potassium and sodium methylate, ethylate, nand iso-propylate, and n-, iso-, sec.- and tert.-butylate.

By means of reaction variant (a), the active compounds of the present invention can be prepared easily and in markedly good yields.

Process variant (a) is preferably carried out in the presence of an inert organic solvent (this term includes a mere diluent). Examples of such solvents include aliphatic or aromatic hydrocarbons (which may be halogenated), for example benzine, methylene chloride, chloroform, carbon tetrachloride, benzene, chlorobenzene, toluene, and xylene; ethers, for example diethyl ether, dibutyl ether, dioxan, and tetrahydrofuran; aliphatic alcohols or ketones which have low boiling points, for example methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, methyl isopropyl ketone, and methyl isobutyl ketone; and the like. Lower aliphatic nitriles, for example acetonitrile, propionitrile, and the like, may also be used.

If M is hydrogen in the appropriate starting compound of formula (Ill) above, the reaction according to variant (a) may preferably be carried out in the presence of an acid-binding agent. Examples of these include alkali metal carbonates and bicarbonates or alcoholates, such as potassium carbonate, sodium bicarbonate, sodium carbonate, or sodium or potassium methylate or ethylate, or aliphatic, aromatic or heterocyclic tertiary bases such as triethylamine, diethylaniline, pyridine, and the like. Instead of using an acidbinding agent, a salt of the 2-nitro-4-alkoxy-phenol of formula (III) above may be prepared, preferably an alkali metal or ammonium salt, and then this salt may be reacted with the starting 0-alkyl-N-isopropyl-amidothiono-phosphoric acid ester halide of formula (II) above.

The reaction according to process variant (a) may be carried out within a fairly wide temperature range, but in general at temperatures from substantially between about 30l C, preferably between about 4070 C.

In carrying out process variant (b) one may for example proceed as follows.

1 mol of alkali metal or ammonium salt of 2-nitro-4- alkoxy-phenol of formula (III) above is dissolved in one of the above-noted solvents, preferably alcohol, and the solution is added dropwise to 1 mol of N-isopropylamidothionophosphoric acid dihalide of formula (IV) above and the mixture is heated at 4570 C for a short time. Then the mixture is cooled to room temperature and mixed with 1 mol of alcoholic solution of alkali metal alcoholate. For completing the reaction, the reaction mixture is again heated at 40-70 C for a short time and excess alcohol is distilled off under reduced pressure. The residue is dissolved in a water-immiscible solvent, preferably one of the aforementioned-hydrocarbons or ethers, and the solution is washed with water. After washing with a solution of dilute alkali metal hydroxide or ammonium hydroxide, the organic phase is dried and finally, by removing the solvent by distillation, the desired compound is obtained as the residue.

Alternatively, the sequence of adding the starting materialsfor process variant (b) may be reversed. In'

this case, the N-isopropyl-amido-thionophosphoric acid dihalide of formula (IV) above is reacted at first with, e.g., an alkali metal alcoholate, solution of an alcoholate of formula (V) above, and then the intermediate product formed is reacted with the 2-nitro-4- alkoxy-phenol of formula (lll) above. When applying this alternative, the conditions of the reaction may be the same as those mentioned above.

Advantageously, the instant active compounds exhibit a strong herbicidal potency and can therefore be used as germination inhibiting agents or weed-killers. By weeds in the sense used herein are meantall plants which grow in places where they are not desired. Whether the active compounds according to the present invention act as total or selective herbicidal agents depends on the amount applied, as the artisan will appreciate.

The active compounds according to the present invention can be used for example in the case of the following plants: dicotyledons, such as mustard (Sinapis), cress (Lepidium), catch weed (Galium), common chickweed (Srellaria), camomile (Matricaria), French weed (Galinsoga), goose-foot (Chenopodium), stinging nettle Urtica), groundsel (Senecio), wild amaranth (Amaranthus), common purslane (Portulaca), cotton (Gossypium), beets (Beta), carrots (Daucus), beans (Phaseolus), potatoes (Solanum), coffee (Coflea), cabbage (Brassica), spinach (Spinacia); monocotyledons, such as timothy (Phleum), meadowgrass (Poa), fescue (Festuca), finger grass (Digitaria), goosegrass (Eleusirie), green foxtail (Setaria), raygrass (Lolium), cheat (Bromus), barnyard grass (Echinochloa), maize (Zea), rice (Oryza), oats'(Avena), barley (Hordeum), wheat (Triticum), millet (Panicum) and sugar cane (Saccharum); and the like. I

The instant compounds are preferably used as selective herbicides and especially when applied to soil before germination, although they exhibit a particularly good selectivity when applied before and after emergence, e.g., in upland and paddy fields where cucumber, tomato, cotton, sugar beet, carrots, beans, potatoes, coffee, cabbage, spinach, raddish maize, rice, oats, barley, wheat, millet and sugar cane are cultivated.

Significantly, the active compounds of the present invention are distinguished by the fact that they are not phytotoxic to rice plants although they are markedly effective in small dosages as compared with PCP and NIP, i.e., compounds (A) and (B), etc. which have hitherto been used widely as herbicides in paddy fields. Furthermore, the same effect as with CAT or Simazin, i.e., compound (C), is generally achievable using the instant active compounds without any harm to crops when applied to soil before germination for controlling weeds in upland fields. Especially when applied to soil before germination, the instant compounds are far better than the already known herbicides in that such instant compounds show a superior selective herbicidal activity, depending on the amount applied.

The active compounds according to the present invention significantly also show a secondary insecticidal and fungicidal activity, e.g., against insects and phytopathogenic fungi which infest plants.

The active compounds according to the instant invention can be utilized, if desired, in the form of the usual formulations or compositions with conventional inert (i.e., plant compatible or herbicidally inert) pesticidal diluents or extenders, i.e., diluents or extenders of the type usable in conventional pesticidal formulations or compositions, e.g., conventional pesticidal dispersible carrier vehicles, such as solutions, emulsions, suspensions, emulsifiable concentrates, spray powders, pastes, soluble powders, dusting agents, granules, etc. These are prepared in known manner, for instance by extending the active compounds with conventional pesticidal dispersible liquid diluent carriers and/or dispersible solid carriers optionally with the use of carrier vehicle assistants, e.g., conventional pesticidal surfaceactive agents, including emulsifying agents and/or dispersing agents, whereby, for example, in the case where water is used as diluent, organic solvents may be added as auxiliary solvents. The following may be chiefly considered for use as conventional carrier vehicles for this purpose: inert dispersible liquid diluent carriers including inert organic solvents, such as aromatic hydrocarbons (e.g., benzene, toluene, xylene, etc.), halogenated, especially chlorinated, aromatic hydrocarbons (e.g., chloro-benzenes), paraffms (e.g., petroleum fractions), chlorinated aliphatic hydrocarbons (e.g., methylene chloride, etc.), alcohols (e.g., methanol, ethanol, propanol, butanol, etc.), ethers, ether-alcohols (e.g., glycol monomethyl ether, etc.), amines (e.g., ethanolamine, etc.), amides (e.g., dimethyl formamide, etc.), sulfoxides (e.g., dimethyl sulfoxide, etc. ketones (e.g.,

acetone, etc. and/r water; as well as inert dispersible finely divided solid carriers, such as ground natural minerals (e.g., kaolins, alumina, silica, chalk, i.e., calcium carbonate, talc, kieselguhr, montmorillonite, clay, etc.), and ground synthetic minerals (e.g., highly dispersed silicic acid, silicates, e.g., alkali silicates, etc.); whereas the following may be chiefly considered for use as conventional carrier vehicle assistants, e.g., surface-active agents, for this purpose: emulsifying agents, such as non-ionic and/or anionic emulsifying agents (e.g., polyethylene oxide esters of fatty acids, polyethylene oxide ethers of fatty alcohols, alkyl sulfonates, aryl sulfonates, etc., and especially alkyl arylpolyglycol ethers, magnesium stearate, sodium oleate, etc. and/or dispersing agents, such as lignin, pulp sulfite waste liquors, methyl cellulose, etc.

As will be appreciated by the artisan, the active compounds according to the instant invention may be employed alone or in the form of mixtures with one another and/or with such solid and/or liquid dispersible carrier vehicles and/or with other known compatible active agents, especially plant protection agents, such as other herbicides, or fungicides, insecticides, acaricides, nematocides, bactericides, plant growth regulators, soil disinfectants, etc., including phenoxy compounds, chlorophenol compounds, carbamates, diphenyl ethers, and triazine compounds, and other known agricultural chemicals and/or fertilizers, etc., if desired, or in the form of particular dosage preparations for specific application made therefrom, such as solutions, emulsions, suspensions, powders, pastes, and granules which are thus ready for use.

As concerns commercially marketed preparations, these generally contemplate carrier composition mixtures in which the active compound is present in an amount substantially between about 0.1 and 95% by weight, and preferably 0.5 and 90% by weight, of the mixture, whereas carrier composition mixtures suitable for direct application or field application generally contemplate those in which the active compound is present in an amount substantially between about 0.005l0%, preferably 0.008-%, by weight of the mixture. Thus, the present invention contemplates over-all compositions which comprise mixtures of a conventional dispersible carrier vehiclesuch as (l) a dispersible inert finely divided carrier solid, and/or (2) a dispersible carrier liquid such as an inert organic solvent and/or water preferably including a surface-active effective amount of a carrier vehicle assistant, e.g., a surface-active agent, such as an emulsifying agent and/or a dispersing agent, and an amount of the active compound which is effective for the purpose in question and which in generally between about 0.00595%, and preferably 0.00895%, by weight of the mixture.

In particular, the amount of active compound applied per unit area varies according to the purpose intended, i.e., the effect desired, and the mode of application. In general, higher quantities of substantially between about 5-40 kg of active compound per hectare are applied for total or nonselective herbicidal activity, whereas lower quantities of substantially between about 1.25-5 kg. of active compound per hectare are applied for selective herbicidal activity, these amounts per unit area being irrespective of whether or not a carrier vehicle is also present.

The active compounds can also be used in accordance with the well-known ultra-low-volume process with good success, i.e., by applying such compound if normally a liquid, or by applying a liquid composition containing the same, via very effective atomizing equipment, in finely divided form, e. g., average particle diameter of from 50-100 microns, or even less, i.e., mist form, for example by airplane crop spraying techniques. Only up to at most about a few liters/hectare are needed, and often amounts only up to about 1 quart/acre, preferably 2-16 fluid ounces/acre, are sufficient. In this process it is possible to use highly concentrated liquid compositions with said liquid carrier vehicles containing from about 20 to about by weight of the active compound or even the active substance alone, e.g., about 20lOO% by weight of the active compound.

While the active compounds can be used particularly effectively according to the pre-emergence method, they are also effective when used according to the postemergence method.

Especially when application is carried out mainly before the germination of cultivated plants, the general conditions of cultivation are not so important, but the quantity of active compound to be applied per unit area and the application method are important, as the artisan will appreciate.

Furthermore, the present invention contemplates methods of selectively killing, combatting or controlling undesired plants, e.g., weeds and the like, which comprise applying to at least one of (a) such weeds and (b) their habitat, i.e., the locus to be protected, a herbicidally effective or toxic, amount of the particular compound of the invention alone or together with a carrier vehicle as noted above. The instant formulations or compositions are applied in the usual manner, for example by spraying, atomizing, scattering, dusting, watering, sprinkling, and the like, whether for preemergence application to the soil or post-emergence application to the weeds.

It will be realized, of course, that in connection with the pre-emergence use of the instant compounds as well as the post-emergence use thereof, the concentration of the particular active compound utilized in admixture with the carrier vehicle, and the amounts applied per unit area, will depend upon the intended application and may be varied within a fairly wide range depending upon the weather conditions, the soil, the purpose for which the active compound is used, e.g., for total or only selective herbicidal effect, and the plants which are to be controlled or protected. Therefore, in special cases, it is possible to go above or below the aforementioned concentration ranges and amounts per unit area.

The following illustrate, without limitation, examples of formulations which may be used in accordance with the present invention:

FORMULATION A 5% by weight of instant compound (1), and 95% by weight of a mixture of talc and clay (3:1) are formulated into a dust by mixing and crushing. It is applied as is by dusting to weed and/or their habitat.

FORMULATION B 20% by weight of instant compound (4), 75% by weight of a mixture of talc and clay (3:1 3% by weight of sodium alkylbenzene sulfonate, and 2% by weight of sodium dinaphthylmethane disulfonate are formulated into a wettable powder by mixing and crushing. It is diluted with water at the concentration of l to 500, and applied by spraying to weeds and/or their habitat.

FORMULATION C 20% by weight of instant compound (4), 75% by weight of xylol, and by weight of emulsifier Sorpol (trade name of polyoxyethylenealkylarylether) are formulated into an emulsifiable concentrate by mixing and stirring. It is diluted with water at the concentration of 1 to 1,000 and applied by spraying to weeds and/or their habitat.

FORMULATION D Instant compound (5) is dissolved in xylol, and the solution is sprayed onto clay granules while rotating and mixing so that about by weight of the active compound is contained thereon. The granular formulation is applied by scattering on the surface of soil.

The herbicidal effectiveness of the particular new compounds of the present invention is illustrated, without limitation, by the following Examples:

EXAMPLE 1 Test against weeds of paddy fields Preparation of active compounds: Carrier vehicle 5 parts by weight of acetoneor 5 parts by weight of talc Emulsifier 1 part by weight of benzyloxypolyglycolether To produce a suitable preparation of the particular active compound, 1 part by weight of such active compound is mixed with the stated amount of carrier vehicle and the stated amount of emulsifier intimately, and the resulting emulsifiable concentrate or wettable powder is then diluted with water to the desired final concentration. Test method:

Pots of l/5,000 a. are charged with paddy field soil and then filled with water. Paddy rice seedlings (Kinmaze variety) of 3 to 4 leaves stage are transplanted into the pots under irrigated conditions. After the seedlings have taken root, seeds of barnyardgrass and broad-leaved weeds are sown and spikerush are planted in such pots simultaneously.

The preparations of the given active compound are sprayed at the rate of 500, 250 and 125 g of active compound per l 0 a. onto the soil of pots. After 3 weeks, the degree of damage against the barnyardgrass, spikerush and broadleaved weeds and the phytotoxicity to the paddy rice are determined and characterized by the values 0 to 5, which have the following scales:

Phytotoxieity Herbicidal efficacy v5 Plants are completely dead 4 Remarkable damage 3 Marked damage 2 Small damage l Slight damage 0 No phytotoxicity The particular active compounds tested and the results obtained can be seen from the following Table 1:

TABLE 1 Herbicidal effect against weeds of paddy fields and phytotoxicity to rice Active Amount Phyto- Compound of active Herbicidal effect toxicity No. compound barnin g] 10a. yard- M spikebroadpaddy m grass rush leaved rice weeds Compounds of Invention I25 5 4 5 O 500 5 5 5 O (2,) 250 4 4 5 0 4 3 4 0 500 5 5 5 0 (3,) 250 4 3- 4 5 0 125 4 3 4 0 500 5 5 5 0 (4,) 250 5 5 5 0 I25 5 4 5 O 500 5 5 5 0 1) 250 5 4 5 O l25 5 4 5 0 500 5 5 5 O (6,) 250 5 4 5 O 125 4 3 4 0 500 5 5 5 0 (7,) 250 4 4 5 0 125 4 3 4 0 Known Compounds- Comparison (A) penta- 500 5 3 5 0 chloro phenol 250 3 0 2 0 125 l O O 0 (B) 2,4-di- 500 5 5 5 3 chloro-phenyl- 250 5 5 5 1 4'-nitro- 125 3 l 2 0 phenyl ether Control O 0 O 0 NOTES:

l. Broad-leaved weeds are Monochoria, Rolala indica Koelme, Lindemia pyxidaria, Gratioln japanica Miquel, etc.

2. Compounds of invention have corresponding numbers to those in Table 4 below.

EXAMPLE 2 Test against weeds of upland fields Preparation of active compounds: Carrier vehicle 5 parts by weight of aceton or 5 parts by weight of talc Emulsifier 1 part by weight of benzyloxypolyglycolether To produce a suitable preparation of the particular active compound, 1 part by weight of such active compound is mixed with the stated amount of carrier vehicle and the stated amount of emulsifier intimately, and the resulting emulsifiable concentrate or wettable powder is then diluted with water to the desired final concentration. Test method:

Pots of 30 X 30 cm are charged with soil of diluvial volcanic ash. Seeds of the below-mentioned weeds, upland rice (I-Iataminori variety) and vegetables are sown, and then the preparations of the given active.

scales: Herbicidal efficacy 5 Plants are completely dead or no germination occurs 4 Plants are partially destroyed after germination Phytotoxicity 5 Plants are completely dead or no germination occurs 4 Plants are remarkably damaged after germination centrate is then diluted with water to the desired final concentration.

Phytotoxicity bar Tomato Carrot Seeds of the test plants are sown in normal soil and after 24 hours the preparation of the given active com- 5 pound is sprayed onto the test plants. After 3 weeks,

O-No effect l-Slight damage or slight growth delay 2Marked damage or growth delay Wild Dent amaranth, Common roxtaii purslane Upland Japanese Cucumsetarla thus portulaca rice radish the degree of damage to the test plants is determined and characterized by the values 0 to 5, which have the following meaning:

TABLE;

Herbicidal efiect against weeds of upland fields and phytotoxicity to various crops Herbicidal eflect Barnyard- Finger grass, grass, echinodigiamaranchloa taria or 50% or less germinated damaged after germination or 70% or less germinated 2 Plants are considerably damaged after germination or 70% or more germinated l Plants are slightly damaged after germination or 90% or more germinated 0 No phytotoxicity Amount of active compound, g./10a.

The particular active compounds tested and the results obtained can be seen from the following Table 2.

or or less germinated 3 Plants are remarkably damaged 3 Plants are markedly after germination or or less germinated 2 Plants are markedly damaged after germination or or less germinated l Plants are slightly damaged after germination or or less germinated 0 No effect Active compound number Compounds of invention:

BEES-04 544655655554644 mmmmmmmmmmmmmmmmmmmmm (C) 2-chloro-4,6-bis (ethylamine)-1,3,6-triazine.

their amount per unit area, and the results obtained can be seen from the following Table 3:

Digitarla 40 3-Remarkable damage or only 50% germinated 4Plants are partially destroyed after germination or only 25% germinated 5Plants are completely dead or no germination occurs. The particular active compounds tested, tone) and 1 part by weight of emulsifier (benzyloitv polyglycol ether), and the resulting emulsifiable con- TABLE 8 Pro-emergence soil treatment against various plants (pot test) Cab- Echino- Portu- Cheno- Stel- Ama- Rice Cotton Maize bage chloa lacs podium lana ran Norm-Compounds of invention have corresponding numbers to those in Table 4 below.

EXAMPLE 3 Test of pre-emergence soil treatment against various plants To produce a suitable preparation of the particular active compound, 1 part by weight of such active com- Amount of active com-- pound in kgJha. Wheat Barley son:

pound is mixed with 5 parts by weight of solvent (ace- 45 Active compound number Known compounds, compari- -D5543rdrdrdrd3 QWIOOOAYJuOOO 2 1 Compounds of invention:

azooo on fiooo 1 mm mamm n L 1 l3 14 The test results described in the above-mentioned isopropoxy-plienol are used, respectively, instead of 2 Table 3 show that the compounds of the present invennitro-4-methoxy-phenol. These compounds also have tion have excellent selective herbicidal effect without similar herbicidal activity to the aforementioned comcausing any phytotoxicity to cultivated plants when pound,

used in a suitable quantity (e.g., 1.25 kg 5 kg of active 5 compound per hectare). Especially excellent herbicidal a V H 7 effect is shown against bamyardgrass (Echinochloa), EXAMPLE 5 [reaction variant (a)] fingergrass (Digitaria), common purslane (Portulaca), wild amaranth (Amaranthus), etc.

The following further examples illustrate, without 10 limitation, the process for producing the particular new C330 3 compounds of the present invention. I L 0011; ,H ....s a. M..-

I EXAMPLE 4 [reaction variant (a)] CzHaO B l --O-0CH3 84 g (0.5 mol) of 2-nitro-4-methoxy-phenol are disl-CIH1NII 4, solved in 400 ml of acetonitrile, and 80 g of dried and sifted potassium carbonate are added to the resulting solution. 95 g (0.5 mol) of O-methyl-N-isopropyl- 17.0 g (0.1 mol) of 2-nitro-4-methoxy-phenol are disamido-thionophosphoric acid ester chloride are added solved in 100 ml of acetonitrile, and M0 g of potasdropwise at 50-60 C, with vigorous stirring. The mixsium carbonate are added to the resulting solution. 20 5 ture is heated at 60 C for 5 hours to complete the reacg (0.1 mol) of 0-ethyl-N-isopropyl-amidotion. The inorganic salt produced is filtered off and the thionophosphoric acid ester chloride are added dropfiltrate is distilled to remove the the solvent. The resiwise at 5060 C with vigorous stirring. The mixture is due is dissolvedin 100 ml of benzene. The benzene soheated and further stirred at 70 C for 5 hours to COmlution is washed with a 1% aqueous solution of sodium plete the reaction. The inorganic salt produced is filcarbonate and dried over anhydrous sodium sulfate. tered off and the filtrate is distilled to remove the 501- After distilling off the benzene and recrystallizing the vent. The residue is dissolved in 100 ml of benzene. residue from a carbon tetrachloride/n-hexane mixture, The benzene solution is washed with 1% solution of so- 1 10 g of 0-( 2-nitro-4-methoxy-phenyl)-0-methyl-N- dium carbonate, dried over anhydrous sodium sulfate isopropyl-phosphoro-amidothioate, m.p. 69-70 C, and distilled off. The crude product is extracted with a are obtained. carbon tetrachloride/nhexane mixture. By distilling off In an analogous manner, O-(2 -nitro-4-methoxythe solvent, 25 g of O-(2-nitro-4-methoXy-phenyl)-0- phenyl)-0-isopropyl-N-isopropyl-phosphoro-amidoethyl-N-isopropylphosphoro-amido-thioate, n9 thioate, n 1.5369, (6 having similar herbicidal ac- 1.5 370, are obtained. tivity, is obtained when the corresponding O-isopropyl- In an analogous manner, 0-(2-nitro-4-ethoxy- N-isopropyl-amido-thiono-phosphoric acid ester chlorphenyl)-O-ethyl-N-iso-propyl-phosphoro-amidoide is used instead of O-methyl-N-isopropylamidothioate (5 and O-(2-nitro-4-isopropoxy-phenyl)-0- thionophosphoric acid ester chloride. ethyl-N-isopropyl-phosphoro-amidothioate (8,) are The following Table 4 illustrates appropriate data for obtained when 2-nitro-4-ethoxy-phenol or 2-nitro-4- typical compounds of the present invention.

Table A TICFBgTdtTEl Structural Formula r\1T st i r I o CH O U-(2n1t IO- I-HVHYllORfJ- 3 ll 1 phony]-)-U-morhvl l-( -OCH- i sonropyl -nhosphoro- H v amido-thiomca N0 (H (l O h 0-(2-nitro-4-ethoxy- 3 ll phony].)-U-,me Chy1-.J- P-O -Ut. l-i isopropyl-phosphot oamido-t hioate 8 N Cl-l 0 H O-(Z-nitro--n-propoxy- 3 t phenyU-O-methyl-H- 3 L 3 7 n tsopropyl-phosphoro- 1C l-l \l-l amido-thioate 8 N0 C H 0 0-(2-nitro-4-methoxy- Z l phenyU-O-ethyl-I- (4 -OCH isopropyl-phosphoroamido-thioate S NU7 C H O. (l-(Z-nitro--ethoxy- (5 H phenyU-(Fethyl-N- 4 '2 5 isopropyl-phosphoroi-C H NH amido-thioate 1 S NL 1-C H O Q-(2-nitroi-methoxy- (6 pheny1)-O-isopropy1- 4 3 N-isopropyl-phosphoro- 1-C H NH amido-thioate N0 C H O O-(2-nitro- -methoxy- 4 '9 ll phenyl )-O-n-buty1-"- (7 P-O OCH isopronyl-phosphoroamido-th'toate 1-... H-JH 3 r 7 "flak 5 12 0 H O H 0- Z-nitroi-isopronoxv- 3 P-0 -OC H '1 phenyU-D-ethyl-l- 2 isopropyl-phosphoroi-C H Nl-l amido-thioate Kit 13 It will be realized b iiiriin that ali'f iiiibrgocontrol aha/"6r elimination o f weeds by selective appliing compounds contemplated by the present invention possess the desired selective or total herbicidal properties, and especially the capability of selectively destroying weeds, as well as a comparatively low toxicity toward warm-blooded creatures and a concomitantly low phytotoxicity with respect to higher plants, enabling such compounds to be used with correspondingly favorable compatibility with respect to warmblooded creatures and higher plants for more effective cation of such compounds to such weeds and/or their habitat. Nevertheless, the instant compounds possess total herbicidal action when used in large quantities, although selective herbicidal action is obtained when used in smaller quantities. As contemplated herein, the term weeds is meant to include not only weeds in the narrow sense, but also in the broad sense, whereby to cover all plants and vegetation considered undesirable for the particular purposes in question.

in which R is alkyl of one-four carbon atoms and R is alkyl of one-four carbon atoms.

2. Method according to claim 1 wherein such compound is used in the form of a mixture with a dispersible carrier vehicle, said compound being present in a he'rbicidally effective amount and constituting substantially between about 0.005-95% by weight of the mixture.

3. Method according to claim 1 wherein such compound is applied in amount of about 5-40 kg per hectare.

4. Method according'to claim 1 wherein such compound is applied in an amount of about 1.25-5 kg per hectare.

5. Method according to claim 1 wherein such compound is selected from the group consisting of:

O-( 2-nitro-4-methoxy-phenyl )-O-methyl-N-isopropylphosphoro-amido-thioate,"

O-( 2-nitro-4-methoxy-phenyl)-O-ethyl-N isopropyl- H phosphoro-amido-thioate, 0-(2-nitro-4-methoxy-phenyl)-0-isopropyl-N- isopropyl-phosphoro-amido-thioate, and 0-(2-nitro-4-methoxy-phenyl)-O-n-butyl-N- isopropyl-phosphoro-amido-thioate.

6. Method as claimed in claim 1 wherein R in the formula is alkyl of from one to three carbon atoms.

7. Method as claimed in claim I wherein R in the formula is alkyl of from one to three carbon atoms and R is methyl.

8. Method as claimed in claim 1 wherein said amidothioate is 0-(2-nitro-4-methoxy-phenyl)-0-methyl-N- isopropyl-phosphoro-amido-thioate.

9. Method as claimed in claim 1 wherein said amidothioate is O-(2-nitro-4-methoxy-phenyl)-0-ethyl-N- isopropyl-phosphoro-amido-thioate.

10. Method as claimed in claim 1 wherein said amido-thioate is O-(2-nitro-4-methoxy-phenyl)-0- isopropyl-N-isopropyl-phosphoro-amido-thioate.

11. Method as claimed in claim 1 wherein said amide-thioate is 0-( 2-nitro-4-ethoxy-phenyl )-0-methyl- N-isopropyl-phosphoro-amido-thioate.

12. Method as claimed in claim 1 wherein said amido-thioate is O-(2-nitro-4-n-propoxy-phenyl)-O- methyl-N-isopropyl-phosphoro-amido-thioate.

13. Method as claimed in claim 1 wherein said amido-thioate is 0-(2-nitro-4-ethoxy-phenyl)-0-ethyl- N-isopropyl-phosphoro-amido-thioate.

14. Method as claimed in claim 1 wherein said amido-thioate is 0-(2-nitro-4-methoxy-phenyl)-O-nbutyl-N-isopropyl-phosphoro-amido-thioate. 

2. Method according to claim 1 wherein such compound is used in the form of a mixture with a dispersible carrier vehicle, said compound being present in a herbicidally effective amount and constituting substantially between about 0.005-95% by weight of the mixture.
 3. Method according to claim 1 wherein such compound is applied in amount of about 5-40 kg per hectare.
 4. Method according to claim 1 wherein such compound is applied in an amount of about 1.25-5 kg per hectare.
 5. Method according to claim 1 wherein such compound is selected from the group consisting of: 0-(2-nitro-4-methoxy-phenyl)-0-methyl-N-isopropyl-phosphoro-amido-thioate, 0-(2-nitro-4-methoxy-phenyl)-0-ethyl-N-isopropyl-phosphoro-amido-thioate, 0-(2-nitro-4-methoxy-phenyl)-0-isopropyl-N-isopropyl-phosphoro-amido -thioate, and 0-(2-nitro-4-methoxy-phenyl)-0-n-butyl-N-isopropyl-phosphoro-amido-thioate.
 6. Method as claimed in claim 1 wherein R'' in the formula is alkyl of from one to three carbon atoms.
 7. Method as claimed in claim 1 wherein R in the formula is alkyl of from one to three carbon atoms and R'' is methyl.
 8. Method as claimed in claim 1 wherein said amido-thioate is 0-(2-nitro-4-methoxy-phenyl)-0-methyl-N-isopropyl-phosphoro-amido-thioate.
 9. Method as claimed in claim 1 wherein said amido-thioate is 0-(2-nitro-4-methoxy-phenyl)-0-ethyl-N-isopropyl-phosphoro-amido-thioate.
 10. Method as claimed in claim 1 wherein said amido-thioate is 0-(2-nitro-4-methoxy-phenyl)-0-isopropyl-N-isopropyl-phosphoro-amido -thioate.
 11. Method as claimed in claim 1 wherein said amido-thioate is 0-(2-nitro-4-ethoxy-phenyl)-0-methyl-N-isopropyl-phosphoro-amido-thioate.
 12. Method as claimed in claim 1 wherein said amido-thioate is 0-(2-nitro-4-n-propoxy-phenyl)-0-methyl-N-isopropyl-phosphoro-amido-thioate.
 13. Method as claimed in claim 1 wherein said amido-thioate is 0-(2-nitro-4-ethoxy-phenyl)-0-ethyl-N-isopropyl-phosphoro-amido-thioate.
 14. Method as claimed in claim 1 wherein said amido-thioate is 0-(2-nitro-4-methoxy-phenyl)-0-n-butyl-N-isopropyl-phosphoro-amido-thioate. 